Hydraulic check



Jan. 20, 1942. E. DAVIS HYDRAULIC CHECK Filed May 28, 1940 4 Sheets-Sheet l INVENTOR.

ERNEST DAVIS 45 A TTORNEYS.

Jan. 20, 1942. E. DAVIS 2,270,668

HYDRAULIC CHECK I Filed May 28, 1940 4 Sheets-Sheet 2 I Ill' 1 MW INVENTOR.

ERNEST DAVIS v fim I A T TORNEYS.

Jan. 20, 1942. E. DAV'IS 2,270,668

HYDRAULIC CHECK Filed May 28, 1940 4 Sheets-Sheet 3 9 INVENTOR.

ERNEST DAVIS A TTORNEYS.

Jan. 20, 1942. E. DAVIS 2,270,668

HYDRAULI C CHECK Filed May 28, 1940 4 Sheets-Sheet 4 DOWN CHECK TAPERED ACTION 9 I cl-lEc' 'gms I D! CHECKING F u TAPERED ACTION #4" UP CHECK I I FREE INVENTOR. ERNEST DAVIS A TTORNEYS.

Patented Jan. 20, 1942 U N E STTES NT OFFICE 15 Claims.

adjusted for the situation in which the check is installed.

It further has for its object an equalizing passage connecting the pressure spaces in front of the advance side of the vanes and extending through the piston, so that the checking movement is more accurately adjustable to the control of an adjustable valve in the outlet or fluid transfer port.

It further has for its object a check which is assembled by sleeving the body over the piston member including its vanes.

It further has for its object a piston member in the general form of a spool and with vanes located between the heads of the spool and extending to the axle or hub of the spool, with the heads of the spool having passages opening into end chambers in the body and with the valves, which are adjustable, t control the checking effect in opposite directions located in inwardly extending abutments in the body which divide the interior of the body into piston chambers in which the vanes work respectively,

Other objects will appear throughout the specification.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a side elevation, partly in section, of this hydraulic check.

Figure 2 is a similar elevation, partly broken away, looking upwardly in Figure 1.

Figure 3 is an end view, partly in section, looking to the right in Figure 2 showing the adjustable valve construction.

' Figure 4 is an exploded view in section showing the parts of the body element and the piston element as separated axially.

Figure 5 is a detail isometric view on areduced scale of the piston element.

Figures 6, 7 and 8 are diagrammatic operation views showing the checking effect during relative rocking movement of the body and piston element in one direction for one situation to which this hydraulic check is applicable.

Figure 9 is a side elevation ofa pressing machine showing the checking efiect during the closing thereof effected by the operations shown in Figures 6, 7 and 8..

Figures 10, 11 and 12 are operation views similar to Figures 6, 7 and 8, showing the checking operation during the relative rocking movement of the body element and the piston element in the opposite direction or during the opening of a press.

Figure 13 is a view similar to Figure 9 illustrating the checking effect on the pressing, machine during the opening movement.

The check includes a body element, av rotary piston of the vane type in the body element and an arrangement of ports and passages for a hydraulic fluid for controlling the checking effect during the operation of the piston in one direction or the other.

I designates the body element, this being here shown as including a cylindrical portion 2' provided with a cylindrical interior and heads 3, 4 at its opposite ends, one of these heads, as the head 3, being removable and secured in position as by screws 5. The cylindrical portion 2 of the body is provided with inwardly extending abutments 6, I, preferably located diametrically opposite each other, providing part-cylindricalpiston or vane chambers 8, 9.

l0 designates the piston element located in the body I or the cylindrical portion thereof and having a shaft ll extending through one end of the body, that is, through the head 4 for connection to a part of. the machine, apparatus, etc., the movement of which is to be controlled. The portion of the body I in the heads 3, 4 beyond the ends of the piston or the body constitutes end chambers l2 and I3 or reservoir or transfer chambers for they hydraulic fluid during the. operation of the hydraulic check. The piston I0 is in the general form of a spool including a hub portion l4, heads l5, l6 and vanes I! and [B between the heads. The hub portion l4 coacts with the ends of the abutments 6 and l at l9 and 20, and the heads l5, l6 separate the-part-cylindrical chambers 8, 9 from the end chambers or reservoirs l2, I3v which receive the fluid from the chambers 8, 9 during the operation of the check.

The body element l and the piston element II] are connected to difierent parts of the machine, apparatus, etc., the motions of which are to be checked, and have a relative rocking movement, and in some situations, as when embodied in a pressing machine, the body I is stationary and the pistonv element is capable of rocking within the stationary body element. Each of the abutments 6, 1 is provided with a port 2'! or 22, one

of which, as the port 2| opens at 23 into the part-cylindrical chamber 9, and the other port 22 opening at 24 als into the same part-cylindrical chamber 9. These ports 2|, 22 also communicate through laterally extending transfer passages 25, 26 (Figure 1) formed in the cylindrical wall 2 of the body and opening into the end chambers I2, l3 respectively. Each of the ports 2|, 22 is provided with a suitable valve 21, 28 mounted in a suitable cage 29 or 30 therein and held various distances off the valve seat 3| by an adjustable stem 32 or 32*, the stem 32 being operable to adjust the checking action inone direction, and the stem 32 in the opposite direction. The cages 29, 30 serve as means for securing the abutments to the body.

The part-cylindrical chambers 8, 9 also communicate with the end chambers l2 and I3 through ports 33 and 34 formed into heads l5 and I6 of the piston element, the ports 33 opening int the chamber 8, and the ports 34 into the chamber 9. These ports 33, 34 are arranged to finally pass alongside and be cut off by the abutments 6 and I but at different periods in the movement of the vanes I1, 18. These ports 33 or 34 are here shown as arranged in a series to be successively out off by the abutments.

35 and 36 are equalizing passages extending through the hub portion of the piston element l4 connecting the portions of the chambers 8, 9 on the pressure sides of the piston vanes I1, 18 with respect to the direction in which the piston is moving or rocking, as one side of each vane is the pressure side, when the rocking movement is in one direction, and the reverse side of each vane is the pressure side, when the rocking movement is in the opposite direction. The hub 4 is also provided with a relief passage 3'! arranged to by-pass the hydraulic fluid from one chamber, as the chamber 9, to the chamber 8, which relieves the pressure in the chamber 9 at the final movement of the piston in one direction which, in this embodiment of the invention, is the final portion of the closing movement of the press, so that the press can go under final pressure without checking effect. The end chambers I2 and I 3 are provided with suitable filler openings closed by plugs 38, 39. The shaft II of the piston member ID is provided with an oil tight joint or bearing 40 between it and the head 4 of the body. Preferably, the vanes are assembled in the piston element by a radial movement thereof, the heads l5 and I6 being provided with radial grooves 4| which receive the margins of the vanes l1 and I8, the vanes,

if desired, being permanently secured in position,

as by welding or otherwise assembled in the piston element M. The heads l5, I6 are integral with or fixedly secured to the shaft l4 and the shaft l4 held from displacement in the body or cylinder l by the abutments 6, I, which are in turn fixed in position by the valve casings 29, 39 which extend through the cylindrical wall of the body I and thread into these abutments 6, 1. After the piston has been placed in the cylinder with the abutments loose therein, the shaft l4 can be turned to lift one abutment into position, so that the cage can be threaded thereinto and then the shaft I4 is turned to carry the other abutment into juxtaposition to receive its companion cage. The head I2, which closes the open end of the body or cylinder I through which the parts are assembled in the cylinder, is demountably held in position by the screws 5.

This hydraulic check is here shown (Figures 9 and 13) as applied to a pressing machine PM including a stationary buck B and a press head H movable toward and from the buck to control the closing and opening movements of the head.

The operation of this hydraulic check or movement controlling device in a pressing machine is as follows:

During the closing of the head H from open position A, as seen in Figure 9, the parts of the check are in the position shown in Figure 6, the reservoirs l2 and I3 and piston chambers 8 and 9 are substantially filled with oil or hydraulic fluid. In a pressing machine, duringthe initial starting of the press head from open position, it is desirable to have no checking effect until the static inertia of the head is overcome, and then to have an intermediate checking effect, while the press head is closing to nearly closed position, and then the checking efiect to be again released to minimum, while the press head is going under final pressure. Initially the vanes I! and [8 are in the position A (Figure 6) and the press head H in position A (Figure 9). Thus on the starting of the closing of the press, the hydraulic fluid is free to flow comparatively easily from the chamber 9 through the ports 33, valve controlled port 2| and transfer passages 25, 26 to the reservoir or end chambers l2 and I3. The hydraulic fluid runs freely through the equalizing passage 35 from the advance side of the vane I! to the advance side of the vane I8. During this stage of the operation of the hydraulic check, the vanes l1 and I8 move into position B (Figure 7) and the press head into position B (Figure 9) and the ports 33 move one by one behind the abutment 6 and are cut off progressively, thereby causing a tapering checking action, so that the only outlet for the oil to the reservoir is through the valve controlled port 2|. At the start, as seen in Figure 6, the ports 34 are cut off by the abutment I and then into position to permit a free follow-up transfer of fluid from the end chambers l2, l3 int chamber 9 behind the vane l8. When the press head is in position C (Figure 9) and the piston in position C (Figure 8), the relief passage 3! moves into position to by-pass the hydraulic fluid or from the position shown in Figure 8 into the position shown in Figure 10, during the final closing operation in position D (Figure 13). The vanes are now in position D (Figure 10). During the opening movement of the press, the parts start in theposition shown in Figure 10. During the first part of the opening movement, the hydraulic fluid transfers through the ports 33, 34 into the end chambers l2, l3 and also through the valve controlled port 22, and thence, as before, to the end chambers of the body and equalizes through the passage 36. During this movement, the peripheral transfer passage 31 first .is opened by being opposite to the abutment 6. .During the greater part of the movement, the passage 31 is out of register with the abutment and located entirely in the chamber 9, so that it is ineffective, in so far as transferring pressure is concerned, during the greater part of the movement of the vanes l8 toward the abutment I when the oil is being transferred through the valve controlled passage 22, the transfer passage 36 and the passages 34. The fluid in the chambers 8 and 9 passes through the ports 33, 34 until the piston vanes reach the position E and the head in its opening movement reaches position E (Figure 13), and in the movement to position E, the relief passage 31 has passed out of alinement assembled parts and the checking for opening and closing, up and down, or movements in opposite directions, can be varied to suit the conditions, regardless of the apparatus. in which the checking; device or shock absorber or movement controlling device is installed.

What I claim is: I. A hydraulic check comprising a body element and a piston element having relative rock:

ing movement, the body element being formed with a cylindrical interior andhaving inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body element coaxially with said chambers coacting with the ends of the abutments and having radial vanes extending int the chambers respectively between the abutments, adjustable valve-controlled ports in the abutments, one in. each, opening into only one and the same chamber, and passages in the piston for transferring the fluid from one part cylindrical chamber to the other.

2. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior having diametrically opposite inwardly extending abutments dividing the interior into part-cylindrica1 chambers, the piston element being mounted in the body element coaxially with said chambers, and coacting at its periphery with the ends of the abutments, and having radial vanes extending into the chambers respectively between the abutments, and outlet ports in the abutments leading from one only of the chambers, and adjustable valves in the ports.

3. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior having inwardly extending abutments dividing the interior into part-cylindrical chambers, and the body being formed with a chamber at at least one end thereof, and the piston element being mounted in the body and including a hub portion coacting at its periphery with the inner ends of the abutments and mounted coaxially with the cylindrica1 interior and the piston element being formed with a head dividing the part-cylindrical chambers from the end chamber, said head being formed with ports movable past the abutments to be closedthereby at predetermined stages in the relative rocking movement, the piston element also having radial vanes extending into the, chambers respectively between the abutments, ports in the abutments communicating with one of the chambers and also communicating with the end chamber.

4. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior having inwardly extending abutments dividing the interior into part-cylindrical chambers, and the piston element including a hub portion mounted in. the body element coaxially with said. chambers/and coacting at its periphery with the ends of the abutments and having radial vanes in the partcylindrical chambers respectively, the body element having an end chamber at at least one end thereof, and one of said elements being formed with ports for permitting the passage of. thehydraulic fluid from the part-cylindrical chambers to the end chamber, and equalizing passages ex.- tending through the hub portion of the piston and communicating at its opposite ends with the piston chambers on the advance sides of the vanes.

5. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrica1 chambers, the piston element being mounted in the body element coaxially with said chambers coacting with the ends of the abut.- ments, and having radial vanes; extending into the chambers respectively between the abutments, and adjustable valve-controlled ports. in the abutments, one in each, communicating with one only of the chambers, the piston element having heads forming side walls of the part-cylindrica1 chambers and separating the same from the end portions of the body forming end chambers, and having ports through said heads arranged to pass alongside the abutments and be out ofi thereby during the relative rocking movement.

6. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body element coaxially with said chambers coacting with the ends of the abutments, and having radial vanes extending into the chambers respectively between the abutments, adjustable valve-controlled ports in the abutments, one in each, opening into one only of the chambers, the piston element having heads forming side walls of the part-cylindrical chambers and separating the same from the end portions of the body forming end chambers and having ports through said heads arranged to pass alongside the abutments and be cut oil thereby during the relative rocking movement, the ports in the heads being so located that the ports opening into one cylindrical chamber are cut off at difierent periods of relative rocking, movement from the ports opening into the other partcylindrical chamber.

'7. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body element coaxially with said chambers coacting with the ends of the abutments, and having radial vanes extending into the chambers respectively between the abutments, adjustable valve-controlled ports in the abutments, one in each, opening into one only of the chambers, the piston element having heads forming side walls of the part-cylindrica1 chambers and separating the same from the end portions of the body, forming end chambers and having ports through said heads arranged to pass during the relative rocking movement, the piston element being formed with equalizing passages connecting the portions of the part-cylindrical chambers on the pressure sides of the vanes, with respect to the direction of relative rocking movement.

8. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body element coaxially with said chambers coacting with the ends of the abutments, and having radial vanes extending into the chambers respectively between the abutments, adjustable valve-controlled ports in the abutments, one in each, opening into one only of the chambers, the piston element having heads forming side walls of the part-cylindrical chambers and separating the same from the end portions of the body forming end chambers and having ports through said heads arranged to pass alongside the abutments and be cut off thereby during the relative rocking movement, the piston element being formed with a by-pass arranged to connect the pressure portion of one part-cylindrical chamber with the reverse portion of the other part-cylindrical chamber, as the elements approach the end of their rocking movement in one direction.

9. A hydraulic check comprising a body ele ment and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body element coaxially with said chambers coacting with the ends of the abutments, and having radial vanes extending into the chambers respectively between the abutments, and adjustable valve-controlled ports in the abutments, one in each, opening into one only of the chambers, the piston element having heads forming side walls of the part-cylindrical chambers and separating the same from the end portions of the body forming end chambers and having ports through said heads arranged to pass alongside the abutments and be cut off thereby during the relative rocking movement, the piston element being formed with a peripheral bypass arranged to come into register with the end of one of the abutments, as the elements approach the end of the relative rocking movement in one direction, and thereby connect the pressure portion of one part-cylindrical chamber with the reverse portion of the other part-cylindrical chamber.

10. A hydraulic check comprising a body element and. a piston element having relative rocking movement, the body element being formed with a, cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body element coaxially with said chambers coacting with the ends of the abutments, and having radial vanes extending into the chambers respectively between the abutments, adjustable valve-controlled ports in the abutments, one in each, opening into one only of the chambers, the piston element having heads forming side walls of the part-cylindrical chambers and separating the same from the end portions of the body forming end chambers and alongside the abutments and be cut off thereby having ports through said heads arranged to pass alongside the abutments and be cut off thereby during the relative rocking movement, the piston element being formed with equalizing passages connecting the portions of the part-cylindrical chamber on the pressuresides of the vanes with respect to the direction of relative rocking movement, the piston element being formed with a normally ineffective by-pass arranged to connect the pressure portion of one part-cylindrical chamber with the reverse portion of the other part-cylindrical chamber, as the elements approach the end of their relative rocking movement in one direction.

11. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body element coaxially with said chambers coacting with the ends of the abutments, and having radial vanes extending into the chambers respectively between the abutments, adjustable valve-controlled ports in the abutments, one in each, opening into one only of the chambers, the piston element having heads forming side walls of the part-cylindrical chambers and separating the same from the end portions of the body forming end chambers and having ports through said heads arranged to pass alongside the abutments and be cut off thereby during the relative rocking movement, the ports in the heads being so located that the ports opening into one cylindrical chamber are cut of! at a different period during relative rocking movement than the ports opening into the other part-cylindrical chamber, the piston element being also formed with equalizing passages connecting the portions of the part-cylindrical chambers on the pressure sides of the vanes with respect to the direction of relative rocking movement, and the piston element being also formed with a by-pass arranged to connect the pressure portion of one part-cylindrical chamber with the reverse portion of the other part-cylindrical chamber, as the elements approach the end of the rocking movement in one direction.

12. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body and including a portion mounted in the body in the form of a spool having a hub portion, and discoidal heads at opposite ends of the hub separating the partcylindrical chambers from the end portions of the body and thereby providing end chambers, the hub of the spool coacting with the ends of the abutments, the heads being provided with ports therethrough arranged to pass alongside of and be cut off by the relative rocking movement, outlet ports extending into the abutments and opening into one part-cylindrical chamber only, and independently operable adjustable valves in the ports.

13. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body and including a portion mounted in the body in the form of a spool having a hub portion and discoidal heads at opposite ends of the hub separating the partcylindrical chambers from the end portions of the body, and thereby providing end chambers, the hub of the spool coacting with the ends of the abutments, the heads being provided with ports therethrough arranged to by-pass alongside of and be cut off by the relative rocking movement, outlet ports extending into the abutments and opening into one part-cylindrical chamber only, and independently operable adjustable valves in the ports, the hub portion being formed with equalizing passages extending therethrough connecting the pressure portions of the part-cylindrical chambers on the pressure sides of the vanes with respect to the direction of the relative rocking movement.

14. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and having inwardly extending abutments dividing the interior into part-cylindrical chambers, the piston element being mounted in the body and including a portion mounted in the body in the form of a spool having a hub portion and discoidal heads at opposite ends of the hub separating the partcylindrical chambers from the end portions of the body, and thereby providing end chambers, the hub of the spool coacting with the ends of the abutments, the heads being provided with ports therethrough arranged to pass alongside of and be cut off by the relative rocking movement, outlet ports extending into the abutments and opening into one part-cylindrical chamber only, and independently operable adjustable valves in the ports, the hub portion being formed with equalizing passages extending therethrough connecting the pressure portion of the partcylindrical chamber on the pressure sides of the vanes with respect to the direction of, the relative rocking movement, and the hub being also formed with a peripheral by-pass normally out of eiTective position and movable into position during the relative rocking movement to connect the pressure portion of the part-cylindrical chamber into which the outlet ports open and the reverse portion of the other part-cylindrical chamber, as the elements approach the end of their rocking movement in one direction.

15. A hydraulic check comprising a body element and a piston element having relative rocking movement, the body element being formed with a cylindrical interior and heads at its opposite ends, one head being removable, the body also having inwardly extending radial abutments demountably secured in the body and forming part-cylindrical chambers, the piston element being in the form of a spool having a hub portion and discoidal heads rotatably mounted in the cylindrical wall of the body on opposite sides of the abutments, and also having radial vanes between the head portions movable in the partcylindrical chambers respectively, the hub of the spool formation being rotatably mounted on the end faces of the abutments, the piston element being mountable in the body through the end thereof provided with the demountable head and also having an axial shaft extending through one of the heads of the body, the piston and body elements and the abutments being provided with ports for permitting transfer of hydraulic fluid from and to the part-cylindrical chambers and the body.

ERNEST DAVIS. 

